High-frequency switch

ABSTRACT

A high-frequency switch includes a transmission terminal, an antenna terminal, a reception terminal, and a voltage-control terminal; a first diode, the cathode thereof being electrically connected to the transmission terminal, and the anode being electrically connected to the antenna terminal; a first transmission line, electrically connected between the antenna terminal and the reception terminal; a second diode, the cathode thereof being electrically connected to the reception terminal, and the anode being electrically connected to the voltage-control terminal; a second transmission line, one end thereof being electrically connected to the transmission terminal, and the other end being connected to ground; and a capacitor, electrically connected between the voltage-control terminal and ground. The above high-frequency switch can be miniaturized and has superior performance.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a high-frequency switch, and moreparticularly to a high-frequency switch for being incorporated in amobile communications device and the like.

2. Description of the Related Art

A high-frequency switch is generally used for switching between atransmission circuit and a reception circuit in a digital mobiletelephone and the like. FIG. 6 is an electrical circuit diagram showinga prior art high-frequency switch 1. The anode of a diode D1 isconnected to a transmission terminal Tx. The anode of the diode D1 isgrounded via a series circuit comprising a transmission line 2 and aDC-blocking capacitor C1. A voltage-control terminal Vc1 is connectedvia a resistor Ra at an intermediate connection point between thetransmission line 2 and the capacitor C1. The cathode of the diode D1connects to an antenna terminal ANT.

A reception terminal Rx is connected to the antenna terminal ANT via atransmission line 3. Moreover, the anode of a diode D2 is connected tothe reception terminal Rx. The cathode of the diode D2 is grounded.

Here, the DC-blocking capacitor C1, connected between the transmissionline 2 and the ground, has a large capacitance (approximately 47 pF near1 GHz, and approximately 22 pF near 2 GHz). Since the size of thecapacitor C1 connected between the transmission line 2 and ground islarge, miniaturization of the high-frequency switch 1 is hindered.

Furthermore, in the high-frequency switch 1, when the transmissionterminal Tx and the antenna terminal ANT are connected, isolation mustbe maintained between the antenna terminal ANT and the receptionterminal Rx. When this isolation is poor, insertion loss between thetransmission terminal Tx and the antenna terminal ANT increases.

SUMMARY OF THE INVENTION

The present invention provides a high-frequency switch which overcomesthe above described problems, being small-scale and having superiorperformance.

One preferred embodiment of the present invention provides ahigh-frequency switch comprising:

-   -   a transmission terminal, an antenna terminal, a reception        terminal, and a voltage-control terminal;    -   a first diode, the cathode thereof being electrically connected        to said transmission terminal, and the anode being electrically        connected to said antenna terminal;    -   a first transmission line, electrically connected between said        antenna terminal and said reception terminal;    -   a second diode, the cathode thereof being electrically connected        to said reception terminal, and the anode being electrically        connected to said voltage-control terminal;    -   a second transmission line, one end thereof being electrically        connected to said transmission terminal, and the other end being        connected to ground; and    -   a capacitor, electrically connected between said voltage-control        terminal and ground.

With the above constitution, there is no need for the conventionallarge-capacitance capacitor which was connected on the transmissionterminal side, and it is sufficient to connect only a small-capacitancecapacitor on the reception terminal side. Therefore, the high-frequencyswitch can be miniaturized.

In the above described high-frequency switch, said transmissionterminal, said reception terminal, said antenna terminal, and saidvoltage-controlled terminal may be provided on the surface of amultilayered body; said multilayered body being formed by laminating aplurality of dielectric layers, said first and second transmissionlines, a capacitor electrode of said capacitor and a ground electrode;and said first and second diodes may be mounted on said multilayeredbody. Alternatively, the capacitor may be mounted on the surface of themultilayered body, instead of being contained in the multilayered body.

According to the constitution described above, a high-frequency switchis obtained having a multilayered structure wherein the circuit iscontained within a single component.

Other features and advantages of the present invention will becomeapparent from the following description of embodiments of the inventionwhich refers to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an electrical circuit diagram showing a first embodiment of ahigh-frequency switch according to the present invention.

FIG. 2 is an exploded perspective view of a multilayered high-frequencyswitch having the electrical circuit shown in FIG. 1.

FIG. 3 is a perspective view of the exterior of the high-frequencyswitch shown in FIG. 2.

FIG. 4 is an exploded perspective view of a second embodiment of ahigh-frequency switch according to the present invention.

FIG. 5 is an external perspective view of the high-frequency switchshown in FIG. 4.

FIG. 6 is an electrical circuit diagram showing a prior arthigh-frequency switch.

DESCRIPTION OF PREFERRED EMBODIMENTS

[Embodiment 1, FIG. 1 to FIG. 3]

FIG. 1 is an electrical circuit diagram showing an example of ahigh-frequency switch 21 according to the present invention. The cathodeof a diode D11, forming a switching element, is connected to atransmission terminal Tx. The cathode of the diode D11 is grounded via atransmission line 12. The transmission line 12 functions as a chokeelement. In addition, the anode of the diode D11 connects to an antennaterminal ANT.

A reception terminal Rx is connected via a transmission line 13 to theantenna terminal ANT. Moreover, the cathode of a diode D12 connects tothe reception terminal Rx. The anode of the diode D12 connects to theground via a DC-blocking capacitor C12. A voltage-control terminal Vcconnects via a resistor R11 to an intermediate connection point betweenthe diode D12 and the capacitor C12. A control circuit (not shown) isconnected to this voltage-control terminal Vc, and switches thetransmission lines of the high-frequency switch 21.

A series circuit, comprising a transmission line 14 and a capacitor C13,connects to both ends of the diode D11 (between the anode and thecathode). The transmission line 14 and the capacitor C13 are provided inorder to achieve good isolation when the diode D11 is in the OFF state.

Here, distributed constant lines having a characteristic impedance ofmore than 40 Ω or high-frequency inductors, are used as the transmissionlines 12 and 13. When distributed constant lines are used, the lengthsof the transmission lines 12 and 13 are set within a range of greaterthan λ/12 and less than λ/4 (where λ is the wavelength of a desiredfrequency). A distributed constant line or a high-frequency inductor isalso used for the transmission line 14. Furthermore, floatingcapacitances Cf1, Cf2, and Cf3 are generated between the terminals Tx,ANT, Rx, and ground, and can function as bypass capacitors for impedanceadjustment.

Next, transmitting and receiving using this high-frequency switch 21will be explained. When a positive potential has been applied to thevoltage-control terminal Vc, this potential provides a forward biasvoltage for the diodes D11 and D12. Therefore, the diodes D11 and D12switch to the ON state. Since direct current is blocked by the capacitorC12, the voltage supplied to the voltage-control terminal Vc is appliedto the circuit comprising the diodes D11 band D12.

As a result, a transmission signal which has entered the transmissionterminal Tx passes through the diode D11, and is sent to the antennaterminal ANT. At this time, most of the transmission signal is not sentto the reception terminal Rx. This is because the self-inductance of thediode D12 in the ON state and the capacitance of the capacitor C12resonate in series at the transmission frequency, whereby the impedanceis 0. That is, the transmission lines 12 and 13 operate as a short-stubof length λ/4, and consequently the transmission terminal Tx and theantenna terminal ANT are connected, and the reception terminal Rx isgrounded.

Furthermore, when the voltage-control terminal Vc is at groundpotential, the diodes D11 and D12 switch OFF. Therefore, there is acut-off between the transmission terminal Tx and the antenna terminalANT, and in addition, there is a cut-off between the reception terminalRx and ground. As a result, a received signal which has entered theantenna terminal ANT is sent through the transmission line 13 to thereception terminal Rx, and is mostly not transmitted to the transmissionterminal Tx.

In this way, by controlling the bias voltage applied to thevoltage-control terminal Vc, the high-frequency switch 21 is able toswitch between the respective transmission paths of transmitted andreceived signals.

Moreover, by connecting the cathodes and anodes of the diodes D11 andD12 in the reverse arrangement to that of the cathodes and anodes of thediodes D1 and D2 of the conventional high-frequency switch 1 shown inFIG. 6, the high-frequency switch 21 can dispense with thelarge-capacitance and large-scale DC-blocking capacitor C1 of theconventional high-frequency switch 1. That is, the high-frequency switch21 requires only the small-capacitance and small-scale capacitor C12,connected between the diode D12 and ground on the reception terminal Rxside. The capacitance of the capacitor C12 is, for instance, 10 pF near1 GHz, and 3 pF near 2 GHz. Consequently, the high-frequency switch 21can be miniaturized.

Furthermore, by adjusting the capacitance of the capacitor C12, theisolation between the antenna terminal ANT and the reception terminalRx, which is especially important when the transmission terminal Tx andthe antenna terminal ANT are connected, can be increased more than inthe conventional high-frequency switch. As a result, it is possible toreduce insertion loss between the transmission terminal Tx and theantenna terminal ANT.

Moreover, when transmitting (when the diode D12 is in the ON state), thevoltage-control terminal Vc is shorted to ground, and when receiving(when the diode D12 is in the OFF state), the voltage-controlledterminal Vc is cut-off from the high-frequency signal by the highimpedance of the diode D12, and consequently, it is possible to achievea large isolation between the control circuit connected to thevoltage-control terminal Vc and the high-frequency signal.

And, as shown in FIG. 1, a series circuit comprised of a capacitor C13and a transmission line 14 may be connected to the diode D11 inparallel. In this case, the self-inductance of the diode D11 and theinductance of the transmission line 14 form a parallel resonancecircuit. By matching the resonant frequency thereof with the frequencyof the signal, the impedance at the connection point of the diode D11and the transmission line 14 is increased when the diode D11 is in theON state, and thereby the insertion loss and the reflection loss arereduced. The capacitor C13 is provided for blocking the direct currentvia the transmission line 14.

Next, an example of a laminated-type high-frequency switch having theelectrical circuit shown in FIG. 1 will be explained with reference toFIG. 2 and FIG. 3. As shown in FIG. 2, the high-frequency switch 31comprises dielectric sheets 45 b and 45 c respectively provided withdistributed constant lines 32 a, 32 b and the like, dielectric sheets 45d and 45 g respectively provided with wide-area ground electrodes 35 and36, dielectric sheets 45 e and 45 f respectively provided withdistributed constant lines 33 a, 34 a and 33 b, 34 b, a dielectric sheet45 a provided with peer-hole pads 50 a to 54 b, etc.

The distributed constant lines 33 a and 33 b are for instancespiral-shaped, and are provided on the left side of the sheets 45 e and45 f. The extracted portion 42 a of the distributed constant line 33 ais exposed on the far side near the left side of the sheet 45 e, and theextracted portion 42 b of the distributed constant line 33 b is exposedon the left side of the sheet 45 f. The distributed constant lines 33 aand 33 b are electrically connected in series via a peer-hole 58,provided in the sheet 45 e, and form the transmission line 12.

The distributed constant lines 34 a and 34 b are substantiallymeander-shaped, and are provided on the right side of the sheets 45 eand 45 f. The extracted portion 43 a of the distributed constant line 34a is exposed in the center on the front side of the sheet 45 e, and theextracted portion 43 b of the distributed constant line 34 b is exposednear the right side on the far side of the sheet 45 f. The distributedconstant lines 34 a and 34 b are electrically connected in series via apeer-hole 59, provided in the sheet 45 e, and form the transmission line13.

The distributed constant lines 32 a and 32 b are spiral-shaped, and areprovided on the right side of the sheets 45 b and 45 c. The distributedconstant lines 32 a and 32 b are electrically connected in series via apeer-hole 57, provided in the sheet 45 b, and form the transmission line14. In this way, transmission lines 12 to 14 having fixed impedancecharacteristics each comprise two layers and comprise distributedconstant lines 33 a, 33 b, 34 a, 34 b, 32 a, and 32 b, whereby thelength of a transmission line portion on each one layer can be shorterthan in the conventional art. Therefore, the size of the sheets 45 a-45g can be reduced, obtaining a high-frequency switch 31 which occupies asmall area with respect to a printed circuit substrate or the like.

The ground electrodes 35 and 36 are provided over a wide area on thesurfaces of the sheets 45 d and 45 g. The extracted portions 35 a and 36a of the ground electrodes 35 and 36 are exposed on the left sides ofthe sheets 45 d and 45 g, the extracted portions 35 b and 36 b areexposed on the right, the extracted portions 35 c and 36 c are exposedin the center on the far sides of the sheets 45 d and 45 g, and theextracted portions 35 d and 36 d are exposed near the right side on thefront sides of the sheets 45 d and 45 g. The transmission lines 12 and13 are provided in parallel between these two ground electrodes 35 and36.

Moreover, extracted electrodes 37, 38, 39, and a relay electrode 40 areprovided on the surface of the sheet 45 b on which the distributedconstant line 32 a is provided. Ends of each of the extracted electrodes37 and 38 are exposed near the left side and right side on the far sideof the sheet 45 b, and the end of the extracted electrode 39 is exposednear the left side on the front side of the sheet 45 b. Then, thedistributed constant line 32 a is electrically connected to a peer-holepad 52 b, the extracted electrode 37 is electrically connectedto-peer-hole pads 50 a and 52 a, the extracted electrode 38 iselectrically connected to a peer-hole pad 51 a, and the relay electrode40 is electrically connected to peer-hole pads 53 b, 54 b, and 51 b.

An extracted electrode 41 is provided on the surface of the sheet 45 con which the distributed constant line 32 b is provided. One end of theextracted electrode 41 is exposed in the center of the front side of thesheet 45 c. Then, the extracted electrode 41 is electrically connectedto the distributed constant line 32 b, and in addition, electricallyconnected via the peer-hole 55 to the peer-hole pad 50 b. Furthermore,the peer-hole pad 53 a is electrically connected to the ground electrode35 via the peer-holes 56 a and 56 b provided in the sheets 45 b and 45c.

When all the sheets 45 a-45 g having the above constitutions are piledon top of each other and heat-bonded together, the multilayered body 60shown in FIG. 3 is obtained. A transmission terminal Tx, a groundterminal G3, and a reception terminal Rx are provided on the left side,the center, and the right side of the side face portion on the far sideof the multilayered body 60. A voltage-control terminal Vc, an antennaterminal ANT, and a ground terminal G4 are provided on the left side,the center, and the right side of the side face portion on the frontside of the multilayered body 60. Ground terminals G1 and G2 areprovided on the left and right side face portions of the multilayeredbody 60.

The transmission terminal Tx is electrically connected to one end of thetransmission line 12 (specifically, to the extracted portion 42 a of thedistributed constant line 33 a), and to the extracted electrode 37. Thereception terminal Rx is electrically connected to one end of thetransmission line 13 (specifically, to the extracted portion 43 b of thedistributed constant line 34 b), and to the extracted electrode 38. Theantenna terminal ANT is electrically connected to the other end of thetransmission line 13 (specifically, to the extracted portion 43 a of thedistributed constant line 34 a), and to the extracted electrode 41. Thevoltage-control terminal Vc is electrically connected to the extractedelectrode 39. The ground terminal G1 is electrically connected to theother end of the transmission line 12 (specifically, the extractedportion 42 b of the distributed constant line 33 b), and to theextracted portions 35 a and 36 a of the ground electrodes 35 and 36. Theground terminals G2, G3, and G4 are electrically connected respectivelyto the extracted portions 35 b, 36 b, 35 c, 36 c, 35 d, and 36 d of theground electrodes 35 and 36.

Moreover, the cathode electrode and anode electrode of the diode D11 aresoldered to the pads 50 a and 50 b on the multilayered body 60, thecathode electrode and anode electrode of the diode D12 are soldered tothe pads 51 a and 51 b, the terminal electrodes of the capacitor C13 aresoldered to the pads 52 a and 52 b, the terminal electrodes of thecapacitor C12 are soldered to the pads 53 a and 53 b, and the terminalelectrodes of the resistor R11 are soldered to the pads 54 a and 54 b.

This obtains a surface mount-type multilayered high-frequency switch 31having the electrical circuit shown in FIG. 1. This multilayeredhigh-frequency switch 31 does not require a large-capacitanceDC-blocking capacitor C1, as in the conventional high-frequency switch 1shown in FIG. 6, to be incorporated in or mounted on the multilayeredbody 60, and consequently even though the transmission lines 12 to 14each comprise two layers, the number of layers in the multilayered body60 can be reduced. Moreover, the size of the sheets 45 a-45 g can bereduced, reducing the area occupied by the high-frequency switch 31 on aprinted circuit substrate or the like.

Furthermore, in the high-frequency switch 1 shown in FIG. 6, a resistorRa (an external component) was electrically connected at an intermediateconnection point between the transmission line 2 and the capacitor C1,causing complex interconnections. By contrast, in the high-frequencyswitch 31, since one end of the transmission line 12 connects to theground terminal G1, interconnection is simple, thereby enabling thenumber of layers in the multilayered body 60 to be reduced, and leadingto a consequent improvement in transmission loss by eliminatingunnecessary coupling.

[Embodiment 2, FIG. 4 and FIG. 5]

Another example of a multilayered high-frequency switch having theelectrical circuit shown in FIG. 1 will be explained referring to FIG. 4and FIG. 5. The high-frequency switch 61 of this second embodimentcontains a DC-blocking capacitor C12 within its multilayered body. InFIGS. 4 and 5, the same parts as those in FIGS. 2 and 3 are representedby the same reference numerals, and explanation thereof is omitted.

As shown in FIG. 4, the high-frequency switch 61 comprises a dielectricsheet 45 j; comprising a distributed constant line 62 and a capacitorelectrode 70, dielectric sheets 45 d and 45 g comprising wide-areaground electrodes 35 and 36, a dielectric sheet 45 k comprisingdistributed constant lines 63 and 64, a dielectric sheet 45 i;comprising extracted electrodes 37 and 38 and the like, a dielectricsheet 45 h comprising peer-hole pads 50 a and 50 b and the like, etc.

The distributed constant line 62 is for instance meander-shaped, andforms a transmission line 14. One end of the distributed constant line62 is electrically connected to the extracted electrode 41, and theother end is electrically connected to the peer-hole pad 52 b via apeer-hole 67, provided in the sheet 45 i. The distributed constant lines63 and 64 are substantially meander-shaped, and respectively formtransmission lines 12 and 13. One extracted portion 63 a of thedistributed constant line 63 is exposed near the left side on the farside of the sheet 45 k, and the other extracted portion 63 b is exposedthe left side of the sheet 45 k. One extracted portion 64 a of thedistributed constant line 64 is exposed in the center of the front sideof the sheet 45 k, and the other extracted portion 64 b is exposed nearthe right side on the far side of the sheet 45 k. In this way, since thetransmission lines 12 to 14 each comprise one-layer distributed constantlines 63, 64, and 62 respectively, the number of layers of themultilayered body 80 (explained later) can be further reduced.

The capacitor electrode 70 is formed on the sheet 45 j on the sidethereof away from the ground electrode 35, and together with the groundelectrode 35 forms a capacitor C12. The capacitor electrode 70electrically connects via a peer-hole 66 to the relay electrode 65provided on the sheet 45 i. Moreover, the relay electrode 65 iselectrically connected to the peer-hole pads 51 b and 54 b.

When the sheets 45 d and 45 g-45 k of the above constitution are piledon top of each other and heat-bonded together, the multilayered body 80as shown in FIG. 5 is obtained. A transmission terminal Tx, a groundterminal G3, and a reception terminal Rx are provided on the side faceportion at the far side of the multilayered body 80. A voltage-controlterminal Vc, an antenna terminal ANT, and a ground terminal G4 areprovided on the side face portion at the front side of the multilayeredbody 80. Ground terminals G1 and G2 are provided on the left and rightside face portions of the multilayered body 80.

The transmission terminal Tx is electrically connected to the extractedportion 63 a of the distributed constant line 63, and to the extractedelectrode 37. The reception terminal Rx is electrically connected to theextracted portion 64 a of the distributed constant line 64, and to theextracted electrode 38. The antenna terminal ANT is electricallyconnected to the extracted portion 64 a of the distributed constant line64, and to the extracted electrode 41. The voltage-control terminal Vcis electrically connected to the extracted electrode 39. The groundterminal G1 is electrically connected to the extracted portion 63 b ofthe distributed constant line 63, and to the extracted portions 35 a and36 a of the ground electrodes 35 and 36. The ground terminals G2, G3,and G4 are electrically connected to the extracted portions 35 b, 36 b,35 c, 36 c, 35 d, and 36 d of the ground electrodes 35 and 36respectively.

Moreover, the cathode electrode and anode electrode of the diode D11 aresoldered to the pads 50 a and 50 b on the multilayered body 80, thecathode electrode and anode electrode of the diode D12 are soldered tothe pads 51 a and 51 b, the terminal electrodes of the capacitor C13 aresoldered to the pads 52 a and 52 b, and the terminal electrodes of theresistor R11 are soldered to the pads 54 a and 54 b.

This obtains a surface mount-type multilayered high-frequency switch 61having the electrical circuit shown in FIG. 1. Since the capacitor C12has a small capacitance, the area of the capacitor electrode 70 issmaller and it occupies less area when incorporated in the multilayeredbody 80. Therefore, the high-frequency switch 61 can be moreminiaturized than a conventional one.

Moreover, in the high-frequency switch 61, since the capacitor C12 iscontained in the multilayered body 80, the length of the interconnectionfrom the capacitor C12 to ground is shorter than when the capacitor C12is mounted on the multilayered body as an external component. Therefore,there is less residual impedance, improving the DC bias-blocking effect.Moreover, the value of the capacitor C12 can be minutely adjusted bychanging the size of the capacitor electrode 70, a greater isolation canbe achieved between the antenna terminal ANT and the reception terminalRx when the transmission terminal Tx and the antenna terminal ANT areconnected than in a conventional high-frequency switch, and there is areduction in insertion loss between the transmission terminal Tx and theantenna terminal ANT.

[Other Embodiments]

The high-frequency switch according to the present invention is notrestricted to the embodiments described above, and various modificationscan be made thereto within the scope of its main features.

For instance, in the high-frequency switch 21 shown in FIG. 1, theseries circuit comprising the transmission line and the capacitor may beconnected to both ends (between the anode and the cathode) of the diodeD12. Alternatively, capacitors may be connected in parallel to both ends(between the anode and the cathode) of the diodes D11 and D12, inparallel with the series circuit comprising the transmission line andthe capacitor, improving the isolation when the diodes D11 and D12 areOFF. Furthermore, resistances (greater than 10K Ω) may be connected inparallel to both ends of the diodes D11 and D12, in order to stabilizethe voltage when a reverse bias is applied.

Furthermore, in the above embodiments, since a DC bias is applied to theterminals Tx, Rx, and ANT, a separate coupling capacitor for DCbias-blocking may be connected to these terminals Tx, Rx and ANT asrequired.

As is clear from the above explanation, according to the presentinvention, by making the direction of the cathode and anode of the diodethe reverse of that in a conventional high-frequency switch, theconventional large-scale and large-capacitance DC-blocking capacitorconnected in the transmission terminal side becomes unnecessary, and itis only necessary to connect a small-scale and small-capacitanceDC-blocking capacitor in the reception terminal side. Therefore, thehigh-frequency switch can be miniaturized.

Furthermore, by adjusting the capacitance of this small-scale capacitor,a greater isolation between the antenna terminal and the receptionterminal can be obtained than in a conventional high-frequency switch.Therefore, insertion loss between the transmission terminal and theantenna terminal can be reduced. Moreover, when transmitting, thevoltage-control terminal is shorted to ground, and when receiving, thevoltage-control terminal is cut-off from the high-frequency signal bythe high impedance of a second diode, and consequently, a largeisolation can be achieved between the control circuit connected to thevoltage-control terminal and the high-frequency signal. As a result, itis possible to obtain a high-frequency switch of superior performance.

While the invention has been particularly shown and described withreference to preferred embodiments thereof, it will be understood bythose skilled in the art that the foregoing and other changes in formand details may be made therein without departing from the spirit of theinvention.

1. A high-frequency switch comprising: a transmission terminal, anantenna terminal, a reception terminal, and a single voltage-controlterminal; a first diode, the cathode thereof being electricallyconnected to said transmission terminal, and the anode beingelectrically connected to said antenna terminal; a first transmissionline, electrically connected between said antenna terminal and saidreception terminal; a second diode, the cathode thereof beingelectrically connected to said reception terminal, and the anode beingelectrically connected to said single voltage-control terminal; a secondtransmission line, one end thereof being electrically connected to saidtransmission terminal, and the other end being connected to groundwithout a DC-blocking capacitor; and a capacitor, electrically connectedbetween said single voltage-control terminal and ground, and thecapacitor being connected to said second diode in series; wherein aself-inductance of said second diode in an ON state and a capacitance ofsaid capacitor resonate in series at a transmission frequency.
 2. Thehigh-frequency switch according to claim 1, wherein said transmissionterminal, said reception terminal, said antenna terminal, and saidvoltage-control terminal are provided on an outside surface of amultilayered body; said multilayered body comprises a plurality oflaminated dielectric layers, having electrodes thereon, said electrodesconstituting said first and second transmission lines, a capacitorelectrode of said capacitor and a ground electrode; and said first andsecond diodes are mounted on said outside surface of said multilayeredbody and connected to said electrodes.
 3. The high-frequency switchaccording to claim 1, wherein said transmission terminal, said receptionterminal, said antenna terminal, and said voltage-control terminal areprovided on an outside surface of a multilayered body; said multilayeredbody comprises a plurality of laminated dielectric layers havingelectrodes thereon, said electrodes constituting said first and secondtransmission lines; and said first and second diodes are mounted on saidoutside surface of said multilayered body and connected to saidelectrodes.